Convert CWallet::ScanForWalletTransactions and SyncTransaction to the new Chain apis

Only change in behavior is "Rescan started from block <height>" message
replaced by "Rescan started from block <hash>" message in
ScanForWalletTransactions.

Co-authored-by: Ben Woosley <ben.woosley@gmail.com>

src/interfaces/chain.cpp

@@ -60,6 +60,42 @@ class LockImpl : public Chain::Lock
         assert(block != nullptr);
         return block->GetMedianTimePast();
     }
+    Optional<int> findFirstBlockWithTime(int64_t time, uint256* hash) override
+    {
+        CBlockIndex* block = ::chainActive.FindEarliestAtLeast(time);
+        if (block) {
+            if (hash) *hash = block->GetBlockHash();
+            return block->nHeight;
+        }
+        return nullopt;
+    }
+    Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height) override
+    {
+        // TODO: Could update CChain::FindEarliestAtLeast() to take a height
+        // parameter and use it with std::lower_bound() to make this
+        // implementation more efficient and allow combining
+        // findFirstBlockWithTime and findFirstBlockWithTimeAndHeight into one
+        // method.
+        for (CBlockIndex* block = ::chainActive[height]; block; block = ::chainActive.Next(block)) {
+            if (block->GetBlockTime() >= time) {
+                return block->nHeight;
+            }
+        }
+        return nullopt;
+    }
+    Optional<int> findPruned(int start_height, Optional<int> stop_height) override
+    {
+        if (::fPruneMode) {
+            CBlockIndex* block = stop_height ? ::chainActive[*stop_height] : ::chainActive.Tip();
+            while (block && block->nHeight >= start_height) {
+                if ((block->nStatus & BLOCK_HAVE_DATA) == 0) {
+                    return block->nHeight;
+                }
+                block = block->pprev;
+            }
+        }
+        return nullopt;
+    }
     Optional<int> findFork(const uint256& hash, Optional<int>* height) override
     {
         const CBlockIndex* block = LookupBlockIndex(hash);
@@ -116,6 +152,11 @@ public:
         }
         return true;
     }
+    double guessVerificationProgress(const uint256& block_hash) override
+    {
+        LOCK(cs_main);
+        return GuessVerificationProgress(Params().TxData(), LookupBlockIndex(block_hash));
+    }
 };
 
 } // namespace

src/interfaces/chain.h

@@ -58,6 +58,26 @@ public:
         //! will abort.
         virtual int64_t getBlockMedianTimePast(int height) = 0;
 
+        //! Return height of the first block in the chain with timestamp equal
+        //! or greater than the given time, or nullopt if there is no block with
+        //! a high enough timestamp. Also return the block hash as an optional
+        //! output parameter (to avoid the cost of a second lookup in case this
+        //! information is needed.)
+        virtual Optional<int> findFirstBlockWithTime(int64_t time, uint256* hash) = 0;
+
+        //! Return height of the first block in the chain with timestamp equal
+        //! or greater than the given time and height equal or greater than the
+        //! given height, or nullopt if there is no such block.
+        //!
+        //! Calling this with height 0 is equivalent to calling
+        //! findFirstBlockWithTime, but less efficient because it requires a
+        //! linear instead of a binary search.
+        virtual Optional<int> findFirstBlockWithTimeAndHeight(int64_t time, int height) = 0;
+
+        //! Return height of last block in the specified range which is pruned, or
+        //! nullopt if no block in the range is pruned. Range is inclusive.
+        virtual Optional<int> findPruned(int start_height = 0, Optional<int> stop_height = nullopt) = 0;
+
         //! Return height of the highest block on the chain that is an ancestor
         //! of the specified block, or nullopt if no common ancestor is found.
         //! Also return the height of the specified block as an optional output
@@ -85,6 +105,10 @@ public:
         CBlock* block = nullptr,
         int64_t* time = nullptr,
         int64_t* max_time = nullptr) = 0;
+
+    //! Estimate fraction of total transactions verified if blocks up to
+    //! the specified block hash are verified.
+    virtual double guessVerificationProgress(const uint256& block_hash) = 0;
 };
 
 //! Interface to let node manage chain clients (wallets, or maybe tools for